Desferrando nomes: a trajetória político-pedagógica de Paulo Freire (1959-1964)

Sendo um assunto recente à história do país, e que durante vinte um anos fora tolhido a análise dos estudiosos, devido à censura e a repressão do governo ditatorial, o período anterior ao dia 01 de abril de 1964 vem despertando nos meios acadêmicos a necessidade de novas discussões que sejam capazes de trazer respostas à sociedade a respeito daqueles anos, e que possam gerar perspectivas quanto aos problemas estruturais que ainda hoje não foram solucionados. Por isso, este trabalho visa analisar a trajetória política e pedagógica do professor Paulo Freire, entre os anos de 1959 e 1964, tendo como foco a sua atuação na construção de um novo projeto de alfabetização de jovens e adultos no Brasil, em especial, na cidade de Angicos/RN e reconstruir as reflexões do mesmo acerca da democracia brasileira, da educação, da cultura e da política no citado período.

On the selective removal of steel by laser-assisted vortex machining

Of all laser-based processes, laser machining has received little attention compared with others such as cutting, welding, heat treatment and cleaning. The reasons for this are unclear, although much can be gained from the development of an effcient laser machining process capable of processing diffcult materials such as high-performance steels and aerospace alloys. Existing laser machining processes selectively remove material by melt shearing and evaporation. Removing material by melting and evaporation leads to very low wall plug effciencies, and the process has difficulty competing with conventional mechanical removal methods. Adopting a laser machining solution for some materials offers the best prospects of effcient manufacturing operations. This paper presents a new laser machining process that relies on melt shear removal provided by a vertical high-speed gas vortex. Experimental and theoretical studies of a simple machining geometry have identifed a stable vortex regime that can be used to remove laser-generated melt effectively. The resultant combination of laser and vortex is employed in machining trials on 43A carbon steel. Results have shown that laser slot machining can be performed in a stable regime at speeds up to 150mm/min with slot depths of 4mm at an incident CO2 laser power level of 600 W. Slot forming mechanisms and process variables are discussed for the case of steel. Methods of bulk machining through multislot machining strategies are also presented.